Ultrasonic probes are used in many medical applications. Probes typically include a probe head and a connecting cable that attaches to a processing unit via a connector, along with an optional handle and neck. The probe head contains the ultrasound transducers and reflectors, with wiring from the probe head carried inside the neck and handle to an external location. The wiring typically includes wires for electric power and wires to carry signals from the probe head to the processing unit such as a computer.
A number of medical applications require specialized probes that can be manipulated and directed by the treating physician. For example, U.S. Pat. No. 5,204,622 (McCaslin et al.) discloses a tube inspection probe with a flexible cable which helically moves the probe head assembly through the tube. The patent discloses a mechanism for maintaining the axis of rotation of the cable in alignment with the center of the tube.
U.S. Pat. No. 5,647,367 (Lum et al.) discloses an ultrasonic probe for imaging tissues from inside a patient's body cavity. The probe includes a housing near the probe's distal end which is connected to a pivotable part of an ultrasonic beam emitting assembly. The pivotable part is pivoted through a driver, located near the ultrasound transducer, such that as the pivotable part pivots, it sweeps ultrasonic energy over a selected angle.
U.S. Pat. No. 5,522,394 (Zurbrugg) discloses an implantable ultrasonic probe for measuring the flow velocity of blood in humans and animals. The probe is shaped like a double handled tennis racket (one handle on each side of the head) with the blood vessel running perpendicular to the plane of the racket where the strings of the racket would be.
U.S. Pat. No. 5,469,853 (Law) discloses a bendable ultrasonic probe and sheath used for endosurgical operations. The probe consists of a rigid handle with a bendable section extending straight from the handle. The handle and bendable section are coaxial when the bendable section is not bending.
U.S. Pat. No. 5,398,689 (Conner et al.) discloses an ultrasonic probe assembly which includes a sensor head located at the tip of a flexible shaft. The flexible shaft is attached to and coaxial with a fixed shaft and connected handle.
The prior art generally falls into two categories: a pivotable head on the end of a shaft so that an ultrasound transducer can be rotated in different directions, or a head on a flexible portion that is connected to a fixed straight portion that extends straight out from a handle. There exists a need for a probe designed such that a relatively small sensor head at the tip of the probe can be inserted easily into deep surgical access openings so that the surgeon's hand holding the handle does not occlude the surgeon's view while precisely locating the sensor head around a small blood vessel.